Hmm, just curious. I'm going to be having a tank built next year. And have been looking at a ton of boxes. I really like this design. And that its shallower in the rear of the tank by 2 inches which means I can add 2 inches of tank depth. But with that said the overflow box will be against the wall so I dont know how accessible it would be to fish out a fish. Is the slot completely submerged? Or Is it just enough that water flows through?